Human physiological and metabolic responses to an attempted winter crossing of Antarctica: the effects of prolonged hypobaric hypoxia.

An insufficient supply of oxygen to the tissues (hypoxia), as is experienced upon high-altitude exposure, elicits physiological acclimatization mechanisms alongside metabolic remodeling. Details of the integrative adaptive processes in response to chronic hypobaric hypoxic exposure remain to be sufficiently investigated. In this small applied field study, subjects (n=5, male, age 28-54years) undertook a 40week Antarctica expedition in the winter months, which included 24weeks residing above 2500m. Measurements taken pre- and postexpedition revealed alterations to glucose and fatty acid resonances within the serum metabolic profile, a 7.8 (+/- 3.6)% increase in respiratory exchange ratio measured during incremental exercise (area under curve, P>0.01, mean +/- SD) and a 2.1(+/- 0.8) % decrease in fat tissue (P<0.05) postexpedition. This was accompanied by an 11.6 (+/- 1.9) % increase (P>0.001) in VO2 max corrected to % lean mass postexpedition. In addition, spine bone mineral density and lung function measures were identified as novel parameters of interest. This study provides, an in-depth characterization of the responses to chronic hypobaric hypoxic exposure in one of the most hostile environments on Earth.